While I've never seen anyone ask, I'm sure the drivers don't mind. But as I see it, it's just continuing the magic. Just as employees are "cast members" it's all part of a show, so naming the buses this way adds to the magic!

I think most guests would rather see not in service or out of service. I know what it means but just about every time people are asking what is that bus or where does that bus go. You just about always see someone go to the driver and ask.